What Side Goes Down on Weed Blocker Material?

Weed Barrier Choices

• Black plastic was used extensively for years as a weed barrier fabric, but its use has waned as better products have become available. Black plastic suppresses weed growth, but also reduces water and air flow to plants. It tears easily and must be replaced frequently. Woven or perforated fabrics allow water and air to flow through, but may also allow weeds to grow more quickly than other fabrics. Spun-bond weed barriers are heavyweight and usually cost more than other materials. They allow air and water to reach the soil, but don't tear easily and reduce weed growth most effectively. Because of their weight, they are more cumbersome to install than other products.

Installation

• To install weed barrier fabric, roll the fabric out so the curled edge faces downward for easiest installation. Cut the fabric to fit the garden space and secure it with landscape pins. Cut holes in the fabric for plants. Cover the weed barrier fabric with gravel, rocks or wood chips to create a neat appearance and protect the weed barrier fabric.

Drawbacks

• Weed barrier fabrics break down over time, allowing weeds to grow through the material. Weeds may become entangled in the fabric, making them difficult to remove. Weed barriers become visible through thinning mulches, giving the landscape a sloppy, neglected look. Plan to replace weed barriers every three to five years, depending on the product. Weed barriers also make amending the soil prior to planting difficult and may limit plant growth.

Solutions

• A 3- to 4-inch layer of wood chip mulch suppresses weeds as effectively as weed barrier, but allows more oxygen and water to permeate the soil. Any weeds that appear are easily pulled. As wood chips break down, they add organic matter to the soil, improving its texture. Replace the wood chips every two years for best results.